Apparatus for the production of artificial threads from cuprammonium solution



Nov. 6, 1934. A. ZART ET AL 1,919,925

APPARATUS FOR THE PRODUCTION OF ARTIFICIAL THREADS FROM CUPRAMMONIUMSOLUTION Filed Sept. 6, 1928 M am! A? H lnvews Patented Nov. 6, 1934UNITED STATES wit-25 PATENT OFFICE APPARATUS FOR THE PRODUCTIQN 0FARTIFICIAL THREADS FROM CUPRAM- MONHUM SOLUTION Application September 6,1928, Serial No. 304,208 In Germany October 20, 1927 1 Claim.

The invention relates to an apparatus for the production of particularlytear-resisting artificial threads by the copper oxide ammonia stretchspinning process. This process has been carried out in such a way thatthe threads, after leaving the funnel, have been treated with acid undertension and stretching. In such operations it has been carried out sothat the drawing apparatus eifected the tensioning during the acidtreatment as well as the tensioning by the drawing out of the threads inthe spinning funnel, the flow of the precipitating liquid acting toassist in the spinning funnel.

According to the invention, the process is so carried out that thethreads are only preliminarily formed (preliminarily stretched) by theprecipitating liquid in the spinning funnel and. are so far coagulatedthat they are still plastic at the outlet from the spinning funnel,whereupon the threads are subjected to a second considerable stretchingoutside the spinning funnel and before the definite hardening. Theproportion of the definite stretching outside the spinning funnel to thepreliminary stretching in the spinning funnel is selected to be so largethat the threads receive an increased, hitherto unattained, strength.

The complete hardening of the threads outside the spinning funnel takesplace in the usual manner by acid treatment. The acid treatment can takeplace according to the invention after the threads have left thespinning funnel. The stretching must then, however, approach so closelyto the acid treatment that it is effected before the complete hardeningof the threads takes place under the influence of the acid. The acidtreatment may also be effected immediately after the definite secondstretching.

For carrying out the process according to the invention an apparatus maybe used, in which two drawing devices rotating at different speeds arearranged behind the spinning funnel, for example, a drawing rollerbehind the spinning funnel and a second drawing roller in front of thereel, bobbin, spinning centrifuge or the like, and the second drawingroller running at a higher speed than the first. If the material andproportions of the drawing rollers are so chosen that the threads cannotslip on them, these can govern the proportion of the stretching in thespinning funnel and between the two drawing devices.

the ratio of the friction between them so chosen F that the stretchingby the drawing device does not spread backwards to the spinning funnel,in other words, so that the stretching takes place in the spinningfunnel alone by the speed of the precipitating liquid flowing throughit.

In all of the cases described, the acid treatment can take place eitherjust before or in the second drawing device or on the way from thislatter to the bobbin, reel, spinning centrifuge or the like. A bobbin ora reel may also be used immediately as the second drawing device. Theacid treatment then takes place on it.

An example of construction is illustrated in the drawing of a device inaccordance with the invention.

The figure shows a spinning apparatus with two drawing rollers and aspinning centrifuge.

In the figure, the threads are first of all precipitated and drawn outto a certain degree in a flowing precipitating liquid in a spinningfunnel 1 of the usual kind. The movement of the thread in the spinningfunnel is effected once by the flowing precipitating liquid and then bythe roller 2 driven at a particular speed, the roller 2 being arrangedbehind the usual guide rod 9. Behind the roller 2 a drawing roller 3 isarranged and is driven likewise at a definite but greater speed, theacidifying liquid flowing on to the roller 3 from a channel 4. A guideroller 5 then conducts the thread to the spinning centrifuge 6. Theroller 5 may be driven or not according to the nature of the thread. Acatch bowl '7 is disposed under the roller 3 for the acidifying liquidwhich is conducted off through a pipe 8.

In place of the guide rod 9 a system of, for example, thread conductors,arranged to displace the threads, for example of rods, may be used whichconduct the thread in a zigzag path.

What we claim is:

An apparatus for the production of extremely fine and highlytear-resistant artificial threads by the copper oxide ammonia stretchspinning process, comprising a stetch spinning apparatus in which thethread is preliminarily coagulated in a flowing precipitating liquid, astetching device positioned between the spinning apparatus and the firstdrawing roller to prevent transmission or the drawing force to thefilaments within the nozzle, and means for applying a hardening liquidto the filaments at the last stretching roller.

ARTHUR ZART. FRANZ HOELKESKAMP.

